Mammary Analogue Secretory Carcinoma Research Articles

Mammary analogue secretory carcinoma of salivary glands: histological and immunohistochemical features

PROPOSITO: Recientemente, en el ano 2010, Skalova et al describieron un tumor de glandulas salivales de baja malignidad, el carcinoma secretorio analogo mamario (CSAM), con caracteristicas moleculares, microscopicas e inmunohistoquimicas similares al carcinoma secretorio de la mama. Antes de su descubrimiento fue interpretado como carcinoma de celulas acinares (CCA) por sus similitudes morfologicas. En este estudio presentamos un caso de CSAM de glandula parotida izquierda diagnosticado por su morfologia con el soporte de la inmunohistoquimica (IHQ). METODOS Y RESULTADOS: Paciente varon de 60 anos sin antecedentes patologicos de importancia con un nodulo asintomatico de parotida izquierda de 5 anos de evolucion, que consulta por aumento de tamano del mismo, dolor y eritema de la piel. Se realizo parotidectomia total. La biopsia postoperatoria se estudio con H/E y se realizo inmunomarcacion con mamaglobina, S100 y DGO1. Ki67 para analizar su capacidad proliferativa. El estudio histologico demostro la presencia de areas micro y macroquisticas, quistico-papilares y solidas. Se observaron celulas claras con citoplasma vacuolado o granular con eosinofilia debil y celulas semejantes a histiocitos. La atipia celular estaba ausente. La marcacion inmunohistoquimica resulto positiva para mamaglobina y S100 y negativa para DGO1. En cuanto a Ki 67 se observo una reaccion nuclear positiva con un porcentaje del 10%. CONCLUSIONES: El CSAM es una entidad aun no informada en la literatura odontologica. Es importante conocer sus caracteristicas microscopicas, sus criterios diagnosticos, comportamiento clinico y pronostico. Para su diagnostico diferencial se deben considerar el CCA y el carcinoma intraductal de bajo grado.

Comprehensive genomic profiles of metastatic and relapsed salivary gland carcinomas are associated with tumor type and reveal new routes to targeted therapies

BackgroundRelapsed/metastatic salivary gland carcinomas (SGCs) have a wide diversity of histologic subtypes associated with variable clinical aggressiveness and response to local and systemic therapies. We queried whether comprehensive genomic profiling could define the tumor subtypes and uncover clinically relevant genomic alterations, revealing new routes to targeted therapies for patients with relapsed and metastatic disease.Patients and methodsFrom a series of 85 686 clinical cases, DNA was extracted from 40 µm of formalin-fixed paraffin embedded (FFPE) sections for 623 consecutive SGC. CGP was carried out on hybridization-captured, adaptor ligation-based libraries (mean coverage depth, >500×) for up to 315 cancer-related genes. Tumor mutational burden was determined on 1.1 Mb of sequenced DNA. All classes of alterations, base substitutions, short insertions/deletions, copy number changes, and rearrangements/fusions were determined simultaneously.ResultsThe clinically more indolent SGC including adenoid cystic carcinoma, acinic cell carcinoma, polymorphous low-grade adenocarcinoma, mammary analog secretory carcinoma, and epithelial–myoepithelial carcinomas have significantly fewer genomic alterations, TP53 mutations, and lower tumor mutational burden than the typically more aggressive SGCs including mucoepidermoid carcinoma, salivary duct carcinoma, adenocarcinoma, not otherwise specified, carcinoma NOS, and carcinoma ex pleomorphic adenoma. The more aggressive SGCs are commonly driven by ERBB2 PI3K pathway genomic alterations. Additional targetable GAs are frequently seen.ConclusionsGenomic profiling of SGCs demonstrates important differences between traditionally indolent and aggressive cancers. These differences may provide therapeutic options in the future.

Newly Described Entities in Salivary Gland Pathology.

Salivary glands may give rise to a wide spectrum of different tumors. This review concentrates on 4 salivary gland tumors that have been accepted in the recent literature as new neoplastic entities: mammary analog secretory carcinoma, cribriform adenocarcinoma of minor salivary glands (CASG), sclerosing polycystic adenosis/adenoma (SPA), and the mucinous/secretory variant of myoepithelioma. Mammary analog secretory carcinoma is a distinctive low-grade malignant salivary cancer that harbors a characteristic chromosomal translocation, t(12;15) (p13;q25), resulting in an ETV6-NTRK3 fusion. Cribriform adenocarcinoma (CASG) is a distinct tumor entity that differs from polymorphous low-grade adenocarcinoma by location (ie, most often arising on the tongue), by prominent nuclear clearing, differing alterations of the PRKD gene family, and clinical behavior with frequent metastases at the time of presentation of the primary tumor. Early nodal metastatic disease is seen in most cases of CASG; yet, they are still associated with indolent clinical behavior, making it a unique neoplasm among all low-grade salivary gland tumors. SPA is a rare sclerosing tumor of the salivary glands characterized by the combination of cystic ductal structures with variable cell lining including vacuolated, apocrine, mucinous, squamous, and foamy cells, by prominent large acinar cells with coarse eosinophilic cytoplasmic zymogen-like granules, and by closely packed ductal structures, surrounded by a peripheral myoepithelial layer and stromal fibrosis with focal inflammatory infiltrates. SPA frequently harbors intraductal epithelial dysplastic proliferations ranging from mild dysplasia to severe dysplasia/carcinoma in situ. Moreover, SPA has been proven to be a clonal process by HUMARA assay and is associated with considerable risk of recurrence. Therefore, on the basis of all these newly recognized findings, we believe that SPA is likely a neoplasm, and we suggest the name "sclerosing polycystic adenoma." The mucinous variant of myoepithelioma is a myoepithelial tumor with foci of prominent cytoplasmic clearing frequently containing intracellular mucin material and having signet-ring morphology.

POLYMORPHOUS LOW-GRADE ADENOCARCINOMA OF THE LOWER LIP

Polymorphous low-grade adenocarcinoma (PLGA) is a malignant neoplasm that frequently occurs in the minor salivary glands of palate and oral cavity. We present a case of lower lip swelling with ulceroproliferative growth in a 48-year-old male with more than 20 years’ history of development. Fine needle aspiration cytology smears suggested salivary gland neoplasia. A wide incisional biopsy was performed and histopathologic examination diagnosed PLGA. The patient was referred to an oncology center and has been under follow-up for the last 6 months. The differential diagnosis of PLGA with pleomorphic adenoma, adenoid cystic carcinoma, mammary analogue secretory carcinoma, mucoepidermoid carcinoma, epithelial myoepithelial carcinoma, and papillary cystadenocarcinoma is discussed, as well as the significance of different histochemical techniques for microscopic diagnosis.

Clinicopathologic and molecular characterization of mammary analogue secretory carcinoma of salivary gland origin

BackgroundMammary analogue secretory carcinoma (MASC) is a newly recognized salivary gland tumor that harbors a characteristic balanced chromosomal translocation t (12; 15) (p13; q25) resulting in an ETV6-NTRK3 fusion gene. MethodsRetrospective study of 111 salivary gland carcinomas revealed 37 cases with secretory features and growth patterns resembling secretory carcinoma of breast. These 37 cases were originally diagnosed as acinic cell carcinoma, adenocarcinoma not otherwise specified and cystadenocarcinoma. Positive immunostaining for S-100 protein and mammaglobin, followed by detection of ETV6 gene rearrangement by FISH and/or ETV6-NTRK3 fusion transcript by RT-PCR were used to identify MASCs. ResultsIn the cohort of 37 salivary carcinomas with secretory features we have identified 10 cases of MASC. All 10 MASCs were positive for mammaglobin, S-100 protein and SOX10, while staining for DOG1 and p63 protein were mostly absent. In 7/10 cases, both FISH and RT-PCR were positive while three remaining cases showed break of ETV6 gene by FISH analysis and the RT-PCR was negative. Clinical follow-up data were obtained in 6 out of 10 patients with MASC. In 3 patients cervical lymph node metastases developed, one patient with high grade transformed MASC died with multiple distant bone metastases, and local recurrence was observed in three patients. ConclusionOur clinicopathological data are in keeping with previous studies; in most cases, MASC is a low-grade malignancy with overall favorable prognosis. In rare cases, however, MASC with high-grade transformation may behave aggressively, and these patients could benefit from targeted biological treatment using tyrosine kinase inhibitors.

Abstract CT060: STARTRK-2: A global phase 2, open-label, basket study of entrectinib in patients with locally advanced or metastatic solid tumors harboring TRK, ROS1, or ALK gene fusions

Abstract Background: Entrectinib is a potent, CNS-penetrant, oral inhibitor of the tyrosine kinases TRKA/B/C (encoded by the genes NTRK1/2/3, respectively), ROS1, and ALK with IC50s < 2 nM (biochemical kinase assay). Two Phase 1 studies ALKA-372-001 and STARTRK-1 have enrolled more than 130 patients with advanced or metastatic solid tumors harboring TRKA/B/C, ROS1, or ALK molecular alterations, with or without CNS disease. Previously, we reported an objective response rate of 79% in 24 tyrosine kinase inhibitor-naïve patients with TRK, ROS1, or ALK gene fusions who were treated at doses that achieved therapeutic exposures consistent with the Recommended Phase 2 Dose (RP2D) (Drilon et al, AACR 2016). Entrectinib was well tolerated, with predominantly Grades 1 or 2 adverse events that were reversible with dose modification. Responses were observed in NSCLC, colorectal cancer, mammary analog secretory carcinoma, melanoma, and renal cell carcinoma, as early as 4 weeks after starting treatment and lasting as long as > 2 years. Notably, a complete CNS response was achieved in a patient with SQSTM1-NTRK1-rearranged lung cancer. Methods: STARTRK (Studies of Tumor Alterations Responsive to Targeting Receptor Kinases)-2 is a potentially registration-enabling Phase 2 basket study of entrectinib for the treatment of patients with advanced solid tumors that harbor a TRK, ROS1, or ALK gene fusion. In order to determine enrollment eligibility and assignment to a specific tumor type basket, patients are screened for gene fusions either locally, including by ctDNA, or centrally at Ignyta’s CLIA/CAP diagnostic laboratory using next generation sequencing. The study’s eligibility criteria were designed to maximize enrollment of these rare patients by allowing CNS disease, Eastern Cooperative Oncology Group (ECOG) performance status 2, and any prior line of therapy, with the exception of TRK, ROS1, or ALK inhibitors. Patients with ALK- or ROS1-rearranged NSCLC who had previously been treated with crizotinib and experienced CNS-only progression are also eligible. In addition, a “non-evaluable” basket allows enrollment of patients confirmed to have gene fusions who do not meet all the inclusion or exclusion criteria. Entrectinib is administered orally on a continuous daily dosing regimen, at a dose of 600 mg once-daily in repeated 4-week cycles. Safety is assessed by monitoring of adverse events, laboratory tests, and clinic visits. Tumor assessments (computed tomography (CT) or magnetic resonance imaging (MRI)) of the chest, abdomen, pelvis (depending on tumor type), plus bone and/or brain as applicable, are performed at the end of Cycle 1 and every 8 weeks thereafter. All CT and MRI scans are read by a central independent imaging laboratory using the Response Evaluation Criteria In Solid Tumors (RECIST) v1.1 and the Response Assessment in Neuro-Oncology Criteria (RANO) or RANO - Brain Metastases (RANO-BM), as applicable, for patients with primary or secondary CNS disease, respectively. Blood and tissue are collected at the time of progression for biomarker analyses for potential mechanisms of resistance to entrectinib. Patients remain on study treatment until documented radiographic progression as assessed by blinded independent central review (BICR), development of unacceptable toxicity, or withdrawal of consent. Citation Format: Alexander Drilon, Kamalesh Kumar Sankhala, Stephen V. Liu, Byoung Chul Cho, Collin Blakely, Cheng E. Chee, Marwan Fakih, Jonathan Polikoff, Zachary Hornby, Lisa Schechet, David Luo, Edna Chow Maneval, Pratik S. Multani, Robert C. Doebele. STARTRK-2: A global phase 2, open-label, basket study of entrectinib in patients with locally advanced or metastatic solid tumors harboring TRK, ROS1, or ALK gene fusions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT060. doi:10.1158/1538-7445.AM2017-CT060

Mammary analog secretory carcinoma parotid gland: Case report of a recently described tumor with review of literature

AbstractMammary analog secretory carcinoma (MASC) is a low-grade malignant tumor of salivary glands. It is so named because of its cytohistopahological, immunohistological, and cytogenetic resemblance to secretory carcinoma of the breast. Since the first description of this tumor in 2010, about 70 cases have been reported in literature. We report a case of this recently described tumor in a 21-year-old female. The radiological diagnosis of her parotid swelling was pleomorphic adenoma. The cytological evaluation was suggestive of oncocytoma. The histopathology showed a low-grade malignant neoplasm and the differential included papillary variant of acinic cell carcinoma, oncocytic variant of mucoepidermoid carcinoma, and MASC. Immunohistochemistry confirmed the diagnosis of MASC. We have included a brief review of literature.

Abstract 3727: Plasma inhibitory activity (PIA) is a possible pharmacodynamic marker for clinical development of a next generation pan-TRK inhibitor, ONO-5390556

Abstract Background: Colorectal cancer and Mammary analogue secretory carcinoma harboring Neurotrophic tyrosine receptor kinase (NTRK/TRK) gene rearrangements developed resistance to Entrectinib, ALK/ROS/TRK inhibitor. We previously demonstrated that the next generation pan-TRK inhibitor,ONO-5390556 may potently overcome Entrectinib-resistance mutations. Furthermore, inhibition of Trk phosphorylation in tumors has excellent correlation with the in vivo anti-tumor effect by ONO-5390556 (AACR2016, Kozaki et al). Purpose: Accurate measurement of target inhibition in a phase 1 clinical trial is critical to informing selection of appropriate doses for ONO-5390556 in more advanced clinical trials. Plasma inhibitory activity (PIA) assay has recently been performed as a surrogate assay in clinical trials of FLT3, MET and ALK kinase inhibitors. The assay employs the incubation of Tyrosine Kinase expressing cell lines in aliquots of plasma collected at various time points from patients treated with TKI. Herein, we report the preclinical evaluation of PIA assay in accordance with an inhibition of TRK phosphorylation in tumors. Methods: KM12 cells, human colorectal cancer cell lines expressing TPM3-TRKA, were implanted subcutaneously into nude mice. Mice were randomized when the mean tumor volume was 150-600 mm3. Tumors and blood were collected from mice, 2, 4, 7 and 24 hours after the single treatment of ONO-5390556 with the doses of 0.06 and 0.6 mg/kg. The collected tumors were disrupted and phosphorylated TrkA in tumors was detected by Electrochemiluminescence (ECL). In a PIA assay, KM12 was incubated in plasma from the collected blood for 4 hours and phosphorylated TrkA in the cells was detected by ECL.. Results: Treatment with ONO-5390556 at doses of 0.06, 0.6 mg/kg resulted in a significant inhibition of Trk phosphorylation in tumors up to 24 hours. Compared to inhibition of P-TRK in tumors, the inhibition of P-TRK in PIA sustained until 7 hours but rapidly decreased at 24 hours after administration. The levels of both tumors and PIA showed in a dose-dependent inhibition and an excellent correlation until 7 hours. Inhibition of TRK phosphorylation (PIA/Tumor, %)0.06 mg/kg (2,4,7,24h) : 56.3/41.4 (PIA/Tumor, %), 51.9/53.5, 43.0/66.5, -5.5/51.30.6 mg/kg (2,4,7,24h) : 90.2/84.3, 88.4/93.0, 87.4/95.7, 8.3/83.3Conclusion: We have validated the PIA assay that correlates with the inhibition of P-TRK in tumors. Our results demonstrated that the potential utility of PIA as a PD marker may contribute to determining the effective dose of ONO-5390556 in the clinical development. Citation Format: Ryohei Kozaki, Ryu Fujikawa, Hikaru Kato, Natsuka Goto, Toshio Yoshizawa. Plasma inhibitory activity (PIA) is a possible pharmacodynamic marker for clinical development of a next generation pan-TRK inhibitor, ONO-5390556 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3727. doi:10.1158/1538-7445.AM2017-3727

Pure intraductal carcinoma of the parotid gland: Cytologic findings on FNA sample. Report of one case

One case of intraductal carcinoma of the parotid gland in a 67-year-old male patient is here introduced. The patient, who had a one-year history of a parotid mass, had undergone ultrasound and MRI examination that disclosed a 13x4x3 mm well delimited nodular mass of the accessory lobe of his left parotid gland. Ultrasound-guided Fine Needle Aspiration (FNA) had been performed by the clinician. The obtained smears showed widespread cellular necrosis in which cellular clusters with moderate and focally severe atypias displayed papillary and cribriform architecture and were admixed with sheets of epithelial cells with less striking nuclear atypias, squamous, or apocrine metaplasia. Histopathological examination disclosed a pure intraductal carcinoma of the parotid gland with classical morphology, which was radically excised. The differential cytological diagnosis of pure intraductal carcinoma of salivary glands may be difficult and comprises mucoepidermoid carcinoma as well as "in situ" carcinomas developping in the context of sclerosing polycystic adenosis, mammary analogue secretory carcinoma (MASC) of the salivary glands and cystic variants of salivary adenocarcinoma NOS (formerly called cystadenocarcinomas).

Genomic profiling of breast secretory carcinomas reveals distinct genetics from other breast cancers and similarity to mammary analog secretory carcinomas.

Secretory carcinomas of the breast are rare tumors with distinct histologic features, recurrent t(12;15)(p13;q25) translocation resulting in ETV6-NTRK3 gene fusion and indolent clinical behavior. Mammary analog secretory carcinomas arising in other sites are histopathologically similar to the breast tumors and also harbor ETV6-NTRK3 fusions. Breast secretory carcinomas are often triple (estrogen and progesterone receptor, HER2) negative with a basal-like immunophenotype. However, genomic studies are lacking, and whether these tumors share genetic features with other basal and/or triple negative breast cancers is unknown. Aside from shared ETV6-NTRK3 fusions, the genetic relatedness of secretory carcinomas arising in different sites is also uncertain. We immunoprofiled and sequenced 510 cancer-related genes in nine breast secretory carcinomas and six salivary gland mammary analog secretory carcinomas. Immunoprofiles of breast and salivary gland secretory carcinomas were similar. All the tumors showed strong diffuse MUC4 expression (n=15), and SOX10 was positive in all nine breast and in five out of six salivary gland tumors. All breast secretory carcinomas were triple negative or weakly ER-positive, and all tumors at both the sites expressed CK5/6 and/or EGFR, consistent with a basal-like phenotype. Sequencing revealed classic ETV6-NTRK3 fusion genes in all cases, including in carcinoma in situ of one breast tumor. Translocations were reciprocal and balanced in six out of nine breast and three out of six salivary gland tumors and were complex in three others. In contrast to most breast basal carcinomas, the mutational burden of secretory carcinomas was very low, and no additional pathogenic aberrations were identified in genes typically mutated in breast cancer. Five (56%) breast and two (33%) salivary gland tumors had simple genomes without copy number changes; the remainder had very few changes, averaging 1.3 per tumor. The ETV6-NTRK3 derivative chromosome was duplicated in one breast and one salivary gland tumor, and was the only copy number change in the latter. The findings highlight breast secretory carcinoma as a subtype more closely related to mammary analog secretory carcinoma than to basal/triple negative breast cancers of no special type. Lack of pathogenic mutations in common cancer-related genes suggests that ETV6-NTRK3 alone may suffice to drive these tumors and likely helps explain their indolent behavior.

Use of fluorescent in-situ hybridisation in salivary gland cytology: A powerful diagnostic tool.

Salivary gland cytology is challenging because it includes a diversity of lesions and a wide spectra of tumours. Recently, it has been reported that many types of salivary gland tumours have specific molecular diagnostic signatures that could be identified by fluorescent in-situ hybridisation (FISH). The aim of the present study was to demonstrate the feasibility and efficiency of FISH on routine cytological salivary gland smears. FISH was conducted on 37 cytological salivary gland smears from 34 patients. According to the cytological diagnosis suspected, MECT1/MAML2 gene fusion and rearrangements of PLAG1, MYB, or ETV6 were analysed. The presence and percentages of cells that had gene rearrangements were evaluated. Results were compared with the histological surgical samples, available from 26 patients. The PLAG1 rearrangement was observed in 12/20 (60%) cases of pleomorphic adenoma. MECT1/MAML2 gene fusion was observed in 1:2 mucoepidermoid carcinomas but was not observed in five other tumours (two pleomorphic adenomas, one Warthin's tumour, one mammary analogue secretory carcinoma [MASC] and one cystic tumour). MYB rearrangement was observed in 4/4 adenoid cystic carcinomas. ETV6-gene splitting identified one MASC. Overall, FISH had a specificity of 100% and a sensitivity of 66.7%. When FISH and cytological analyses were combined, the overall sensitivity was increased to 93.3%. It can thus be concluded that when the FISH analysis is positive, the extent of surgery could be determined with confidence pre-operatively without needing a diagnosis from a frozen section.

Nodular oncocytic hyperplasia: Can cytomorphology allow for the preoperative diagnosis of a nonneoplastic salivary disease?

Nodular oncocytic hyperplasia (oncocytosis) of the salivary glands is a benign process that does not inherently require surgical excision. However, cytologic findings in fine-needle aspiration (FNA) of oncocytosis cases have not been well characterized previously, limiting preoperative identification. All available cases of oncocytosis with corresponding FNA specimens were identified from the pathology archives of 3 academic institutions. Clinical, cytologic, and histologic findings were tabulated for all cases. Twelve cases of oncocytosis were identified from 11 patients, including 11 parotid FNA specimens and 1 submandibular FNA specimen. On the original diagnoses, 6 specimens were classified as benign, 4 as atypical, and 2 as nondiagnostic. Oncocytosis was listed in the differential diagnosis in only 1 case. Among diagnostic aspirates, 8 demonstrated low cellularity and 2 demonstrated moderate cellularity. All 10 cases demonstrated oncocytic cells in small to medium groups, with single cells in just 1 case. Spindled and squamous morphology were each noted in 3 cases. Four cases demonstrated cystic change and 1 showed background mucin without goblet cells. No necrosis or mitoses were observed. Although oncocytosis demonstrates some overlap with Warthin tumor and oncocytoma, it lacks the diagnostic findings specific to oncocytic salivary gland malignancies such as salivary duct carcinoma, acinic cell carcinoma, mammary analog secretory carcinoma, and mucoepidermoid carcinoma. Despite current limitations in the understanding of oncocytic salivary gland lesions, the presence of a paucicellular specimen comprised of small groups of oncocytic cells should raise the possibility of oncocytosis in the differential diagnosis and can favor it in elderly patients with multiple salivary nodules. Cancer Cytopathol 2017;125:627-34. © 2017 American Cancer Society.

Systematic review of mammary analog secretory carcinoma of salivary glands at 7 years after description.

Mammary analog secretory carcinoma of the salivary glands (MASCSG ) is a newly introduced malignant tumor of the salivary glands. For decades, it has been confused with acinic cell carcinoma (ACC) of the salivary glands. All reported cases of MASCSG were surveyed from 2010 until January 2017. The collected data was compiled and computationally processed to describe the clinical parameters of MASCSG . Its epidemiology was also mapped. Moreover, inaccurate data was highlighted. Clinically implicating, this article tackles simply the several clinical findings of MASCSG so that our contemporary nosology, at 7 years after description, can be updated. The cytogenetic, histologic, and immunohistochemical details are also defined. The available data about MASCSG is sufficient enough to diagnose it with no need to investigate the ETV6-NTRK3 translocation. Although high-grade malignancy and distant metastases were rarely reported, a rapt attention should be paid both to the nature of this tumor and to the indicated close follow-up of such cases, especially when necrosis, increased mitotic activity, and other classic caveats are conspicuous. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1243-1248, 2017.

Clinical and Morphologic Features of ETV6-NTRK3 Translocated Papillary Thyroid Carcinoma in an Adult Population Without Radiation Exposure.

The ETV6-NTRK3 translocation characterizes a subset of radiation associated and pediatric papillary thyroid carcinomas (PTCs). We now describe the clinicopathologic features of ETV6-NTRK3 translocated PTC in an adult population without radiation exposure. Twelve cases were identified by next-generation sequencing (ThyroSeq version 2). The mean patient age was 37 years with a female predilection (10:2). Preoperative fine needle aspiration was performed on 6 patients of which 4 were classified as "malignant," whereas 2 were classified as "follicular lesion of undetermined significance." One third (4/12) of patients demonstrated extrathyroidal extension and one half of patients (5/10) demonstrated lymph node metastases. One patient presented with brain metastasis. Tumors typically (8/12) demonstrated an admixture of follicular and papillary patterns and were usually infiltrative and multinodular (6/12 cases). Tumors often showed clear cell or oncocytic foci and demonstrated overt nuclear features of PTC, though characteristically, interspersed bland areas were common, even in metastases. Cytoplasmic vacuolization resembling that of mammary analog secretory carcinoma was also common but focal. TTF-1 was positive and S100 was negative in all tested cases confirming a thyroid phenotype. Unique morphologies included glomeruloid follicles, reverse polarization of nuclei. Survey of the TCGA datasets revealed similar findings. Thus, ETV6-NTRK3 translocated PTC are locoregionally aggressive and can metastasize distantly. They are characterized by mixture of papillary and follicular architecture and may show cytoplasmic vacuolization akin to other ETV6 translocated carcinomas. Although nuclear features are typically overt, interspersed bland regions may cause diagnostic difficulty in metastatic sites, and may explain discordance on fine needle aspiration.

Update from the 4th Edition of the World Health Organization Classification of Head and Neck Tumours: Tumors of the Salivary Gland.

The salivary gland section in the 4th edition of the World Health Organization classification of head and neck tumors features the description and inclusion of several entities, the most significant of which is represented by (mammary analogue) secretory carcinoma. This entity was extracted mainly from acinic cell carcinoma based on recapitulation of breast secretory carcinoma and a shared ETV6-NTRK3 gene fusion. Also new is the subsection of "Other epithelial lesions," for which key entities include sclerosing polycystic adenosis and intercalated duct hyperplasia. Many entities have been compressed into their broader categories given clinical and morphologic similarities, or transitioned to a different grouping as was the case with low-grade cribriform cystadenocarcinoma reclassified as intraductal carcinoma (with the applied qualifier of low-grade). Specific grade has been removed from the names of the salivary gland entities such as polymorphous adenocarcinoma, providing pathologists flexibility in assigning grade and allowing for recognition of a broader spectrum within an entity. Cribriform adenocarcinoma of (minor) salivary gland origin continues to be divisive in terms of whether it should be recognized as a distinct category. This chapter also features new key concepts such as high-grade transformation. The new paradigm of translocations and gene fusions being common in salivary gland tumors is featured heavily in this chapter.

Ultrastructural Characterization of Mammary Analogue Secretory Carcinoma of the Salivary Glands: A Distinct Entity from Acinic Cell Carcinoma?

Mammary analogue secretory carcinoma (MASC) of the salivary glands is a recently described neoplasm of the salivary glands with a characteristic morphology complemented by a specific cytogenetic translocation and gene rearrangements. Although immunophenotypic and cytogenetic differences allow for a more reliable distinction, ultrastructural features can also provide important information about the relationship between MASC, classic acinic cell carcinoma (AciCC), and AciCC intercalated duct cell-predominant variant. Following approval from the hospital's institutional review board, 7 cases of MASC, 8 cases of classic AciCC, and 4 cases of AciCC intercalated duct cell-predominant variant were retrieved from the pathology files of Massachusetts General Hospital from 2012 to 2015. Electron microscopy was performed using formalin-fixed, paraffin-embedded tissue. Ultrastructural features of all 19 neoplasms of the salivary glands were recorded. The predominant cell-types observed in MASCare those with intercalated/striated duct cell differentiation. These features include prominent invaginations of the cell surface studded with microvilli, and some intra- and intercellular lumina also with a microvillous surface. Classic AciCC dominant cell-type recapitulates acinar cell differentiation. These cells contain large intracytoplasmic zymogen-like granules. AciCC intercalated duct cell-predominant variant showed both cell populations in various proportions with the intercalated/striated duct cell type usually being the dominant one. MASC presents with distinctive ultrastructural features that allows its proper differentiation from classic AciCC. However, significant ultrastructural features overlaps between both AciCC intercalated duct cells-predominant and classic AciCC and MASC. These findings indicate a very close proximity between these tumors.

Clinicopathologic features of mammary analogue secretory carcinoma of salivary glands

Objective: To investigate the clinicopathological features of mammary analogue secretory carcinoma (MASC) of salivary glands, and its diagnosis, differential diagnosis, immunohistochemistry and molecular pathology. Methods: Seventeen cases of MASC were enrolled, with 9 cases of salivary acinar cell carcinoma and 18 cases of adenoid cystic carcinoma as control groups from Nanjing General Hospital from 1997 to 2014 were included in this retrospective study, combined with immunohistochemistry and molecular detection of ETV6-NTRK3 gene fusion. All cases were histologically reviewed with immunohistochemical staining (EnVision) for S-100 protein, SOX10, GATA3, CD117 expression in each group. Fluorescence in situ hybridization (FISH) was used to detect the ETV6-NTRK3 gene fusion. Results: The age of MASC patients ranged from 27 to 74 years with mean age of 47 and ratio of male and female was 4∶3. All cases showed infiltrative growth and diverse cytology and histology, including lobular (8 cases), cystic papillary (3 cases), cribriform mixed with papillary and glandular structures (6 cases) at various proportions. Some tumors of MASC also exhibited solid growth areas with occasional microcystic honeycombed pattern composed of small cysts merged into larger cysts resembling thyroid follicles. S-100 protein and SOX10 were strongly positive in all MASC cases (17/17). In addition, there was insignificant positivity for GATA3 (3/17) and CD117 (4/17). ETV6 gene fusion detection was informative in 12 MASC cases by FISH with 10 positive cases and 2 negative cases. Conclusions: Combined immunohistochemical positivity of S-100 protein, CD117 and SOX10 are useful in the diagnosis and differential diagnosis of MASC. FISH detection of ETV6-NTRK3 fusion offers an additional molecular diagnostic marker for the diagnosis.

Newly described salivary gland tumors

This review concentrates on three salivary gland tumors that have been accepted in the recent literature as new neoplastic entities: mammary analog secretory carcinoma (MASC), sclerosing polycystic adenoma (SPA) and cribriform adenocarcinoma of tongue and other minor salivary glands (CAMSGs). MASC is a distinctive low-grade malignant salivary cancer that harbors a characteristic chromosomal translocation, t(12;15) (p13;q25) resulting in an ETV6–NTRK3 fusion. SPA is a rare lesion often mistaken histologically for low-grade salivary carcinoma. Previously thought to be a reactive fibroinflammatory process, but recent evidence of clonality, recurrences in up 30%, and dysplastic foci suggest it may be truly neoplastic. CAMSG is a distinct tumor entity that differs from polymorphous low-grade adenocarcinoma (PLGA) by location (ie, most often arising on the tongue), by prominent nuclear clearing, alterations of the PRKD gene family and clinical behavior with frequent metastases at the time of presentation of the primary tumor. Early metastatic disease seen in most cases of CAMSG associated with indolent behavior makes it a unique neoplasm among all low-grade salivary gland tumors. Salivary glands may give rise to a wide spectrum of different tumors. They are often diagnostically challenging as morphological features often overlap between different entities. Although conventional morphology in combination with immunohistochemical findings still provide the most important clues for diagnosis, recent advances in molecular pathology offer new diagnostic tools in investigating the differential diagnosis, as well as providing potentially valuable prognostic indicators. In the last two decades, several new salivary gland tumor entities have been described, namely MASC, SPA and CAMSGs.

Secretory carcinoma - impact of translocation and gene fusions on salivary gland tumor.

Secretory carcinoma (SC), previously described as mammary analogue secretory carcinoma (MASC), is a recently described salivary gland tumor which morphologically resembles mammary secretory carcinoma. The first description of SC/MASC, reported by Skálová et al. in 2010, was as a rare salivary carcinoma imitating secretory carcinoma of the breast. SC/MASC is a unique salivary gland tumor with morphological overlap with acinic cell carcinoma (AciCC), mucoepidermoid carcinoma (MEC), and adenocarcinoma not otherwise specified (ADC-NOS). SC/MASC shares similar clinicopathological features with AciCC. As a critical difference between SC/MASC and AciCC, SC/MASC characteristically has the chromosomal translocation t(12;15)(p13;q25) which leads to a fusion gene between the ETV6 gene on chromosome 12 and the NTRK3 gene on chromosome 15. This genetic background is an important differential diagnostic finding for excluding other salivary gland tumors and may be a critical factor determining the prognosis for patients with SC/MASC. Research in recent years has provided a large body of new data on SC/MASC and suggests the possibility that the ETV6-NTRK3 translocation could be a therapeutic target. Here, we review the morphological and clinicopathological features of SC/MASC and discuss new directions for therapy.

Mammary Analogue Secretory Carcinoma of Salivary Gland. A Case Report Emphasizing its Diagnostic Histological, Immunohistochemistry and Molecular Findings

Mammary Analogue Secretory Carcinoma of Salivary Gland. A Case Report Emphasizing its Diagnostic Histological, Immunohistochemistry and Molecular Findings